Pressure-protecting covering for submarine cables



March 31, 1931.

G. ZAPF,

PRESSURE PROTECTING COVERING FOR SUBMARINE GABLES Filed Oct. 25. 1929 /NVEN Talk Patented Mar. 31, 1931 UNITED STATES PATENT OFFICE GEORG ZAPF, F COLGG-NE, GERMANY,

AF-JEJIGI-FOR TO FELTEI-l' & GUILLEAULIE CARLS- PRESSURE-PROTECTING COVERING FOR SUBIVEARINE CABLES Application filed October 23, 1929, Serial No.

This invention relates to a cable for great sea depths and the object of the invention is to improve the mechanical properties oi? the pressure-protecting coverings hitherto 6 proposed for such cables in order to render them capable of use also for the greatest depths of sea. In some forms of construction the means used for increasing the compressive strength also improved the electric prop- 10 erties of the cable.

A hollow conducto in the form of tube of profile wires may be rendered more resistant to high pressures by the insertion of a twisted strip or of a supporting core of crossshaped cross-section. As compared with a reinforcement of the profile wires for obtain ing the same effect, this arrangement has the advantage that the cable provided with the pressure-protecting covering still possesses a sufficient flexibility.

The invention consists in a pressure-protecting tube having an inner supporting member consisting of a number of separate flat or profile bands which abut against one another radially in the axis of the cable and are stranded together with the profile wires of the pressure-protecting tube. A characteristic of this construction is its increased compressive strength and stability of form.

The accompanying drawing illustrates in cross-section a for i of construction in which the supporting Walls consist of bands the width of which is equal to halt the outer diameter of the pressure-protecting covering and which are stranded together with the pressure-protecting covering. a are the supporting walls 6 and c is a two-layer pressureprotecting covering, d is the lead sheathing and 0 the armouring.

This form of construction has the advantage, that in addition to increasing the compressive strength, the supporting walls can be used at the same time as means for screening the conductors of the groups of conductors of the cable electrostatically with respect to one another. In this way the use of separate screening means is dispensed with.

What I claim is:

1. A pressure-protecting covering for deep sea cables constituted by profile wires and 401,911, and in Germany December 1, 1928.

GEORG ZAPF. 

